Railway signaling



Jan. 24, 1933. P. P. STOKE R RAILWAY SIGNALING Original Filed Feb.'l8,1930 2 Sheets-Sheet 1 INVENTOR:

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Ova-F dust Jan. 24, 1933.

P. P. STOKER RAILWAY S IGNALING L-x'mlzz Uriginal Filed Feb. 18, 1930 2Sheets-Sheet 2 INVENTOR P P, S t o er" m Patented Jan. 24, 1933 UNITEDSTATES ENT PAUL I. STOKER, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THEUNION SWITCH & SIGNALv COMPANY, OF SWISSVALE, PENNSYLVANIA, AGORPORATION OF PENNSYLVANIA Application filed February 18, 1930, SerialMy invention relates to railway signaling, and particularly to signalingfor stretches of single track over which traflic moves in bothdirections. One feature of my invention is the provision, in signalingof this kind, of means controlled from a remote point for permittingseveral cars or trains to pass through a stretch in the same direction,while preventing two cars or trains moving in opposite directions fromoccupying the stretch at the same time.

I will describe one form of signaling apparatus embodying my invention,and will then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1 and 1*, when placed end to endwith Fig. 1 on the left, constitute a diagrammatic view showing one formof signaling apparatus embodying my invention.

Referring to the drawings, the reference character N'designates astretch of railway track between points X and Y, which track is dividedby insulated joints to form a plurality of track sections X1, 12, 7,-Y,Located in the section X1 is a switch L leading into a passing siding P,and located in the section 7Y is another switch L leading into a passingsiding Q.

Each track section is provided with the usual track circuit, comprisinga track battery 8 and a track relay designated by the referencecharacter T with a distinguishing exponent. I

Traflic entering the stretch X-Y from the left is governed by twosignals S and 8 a, according as such traflic enters from the main trackN or the siding P. Tratfic entering the stretch from the right isgoverned by two similar signals S and S a, according as such traffic ison the main track or the siding Q.

Located at the left-hand end of the stretch XY is a despatchers relay Dwhich is controlled by a selector K and which selector is in turncontrolled from a remote point,

' such as a despatchers oflice, over a despatchers line M. When theselector K receives the code to which; it responds, it will close apick-up circuit for relay D which circuit passes from terminal B of asuitable source of current, through the selector K and the RAILWAYSIGNALING No. 429,283. Renewed January 18, 1932;

winding of relay D to terminal 0 of the same source of current. WVhenrelay D becomes energized, a stick circuit for this relay will becomeenergized, which circuit is from terminal B, through the selector Kfront contact 19 of relay D and the winding of relay D to terminal 0.Relay D will then remain energized until a code is transmitted over theline M to operate the selector K in such manner as to open the stickcircuit for this relay.

- Associated with the switch L is a switch repeater relay G which iscontrolled by a pole-changer 31 operated by the switch L in such mannerthat the relay is energized in normal or reverse direction according asthe switch is in its normal or reverse position, but that the relay ismomentarily deenergized during the transit of the switch from eitherposition to the other. The circuit for the relay C will be obvious fromthe drawings.

The apparatus for controlling the signals S and SM involves adirectional relay A a home relay H two slow-releasing relays E and E a,and a stick relay G The right-hand end of the stretch X-Y is providedwith apparatus similar to that just referred to for the lef -hand end,and the parts of this apparatus bear the same reference charactersexcept that they are provided with the exponent 2 instead of theexponent 1.

The operation of the apparatus is as follows:

I will first assume that there is a train moving toward the right andapproaching the stretch XY on the main track N, and that the despatcherdesires to clear the signal S" to admit this train into the stretch. Todo this, he will send the proper code over the transmission line M tooperate the selector K in such manner as to energize the despatchersrelay D Directional relay A will then become energized by virtue of acircuit which passes from terminal 13, through the back point of contact9 of the despatchefs relay D at the right-hand end of the stretch,contacts 10 to 17, inclusive of track relays T to T inclusive, frontpoint of contact 18 of relay D and the winding of relay A to terminal 0.Home relay H will then be- -26 ofrelay D winding of relay H and frontpoint of contact 27 of relay H to terminal 0.

Assuming that switch L is in the normal position, signal relay E willthen become energized, the circuit being from terminal B, throughcontact 28 of relay H neutral contact 29 of switch repeater relay C.polarcontact30 ofthis relay in the left-hand position', and the windingof relay E to terminal 0. Signal S will then be moved to the clearposition by virtue of, a circuit which includes front contact 34 ofrelay E When the train-enters section X1, it will open track relay T andthis will in turn open the circuits for directional relay A and homerelay H The opening of home relay H will, of course, open the circuitfor signal. relay E withthe result that signal S will return to its stopposition. During the time interval between'the opening of track relay Tandthe opening of signal relay E however, a pick-up circuit for stickrelay G will become closed, which circuit is from terminal B, throughback contact 32 of track relay T front contact 33'of relay E and thewinding of relayG to terminal 0. Relay G is provided with twostickcircuits, the first of which is from terminal B, through front contact34 of despatcher relay D back 'contact35 of directional relay A frontcontact 37 of relay G and the winding of this relayto'tenninal' O. Theother stick circuit for relay G is from terminal B, through back contact36 of switch repeater relay C back contact 35 ofrelay A front contact 37ofrelay G and the winding of relay G to terminal 0. It will be seen,therefore, that after relay'Gr' becomes energized,'it willremain-energized as long as the 'despatchers relayD remains closed, orif the despatchers relay D is opened, relay G will remain energizedduring transit of the switch L if this switch should be reversed. Whenrelay G is energized, it closes a branch around contact 25 of relay A inthe circuit for home relay H so that after the train moving toward.the-right'passes point' i, or such other point-as to permit relay H tobecome energized home relay H will again become energized thereby againenergizing signal relay E with the result that signal S will return tothe proceed position, thereby permitting a following train moving towardthe right to enter the stretch If'thetrain moving toward the right is onthe'siding P, the despatcher will, of course, reverse switch L toallow-this trainto pass 'intothe stretch ofsingle track, and this willreverse switch repeater relay C thereby causing'polar contact 30 of thisrelay to' swing to the right. This will result in ener- G controlled bycontact 34 of the despatchefls relay D is, 'of course,.to permitfollowing trains moving toward the rightto enter the .stre tch'-X;Ywithout requiring any action on the part of the despatcher. The purposeof the other stick circuit for relay G -is to per- Init switch L to bemoved from the normalto the reverse position'or vice-versa after theapparatus has been set up to permit a train moving toward the right toenter the stretch If the despatcher desires to admit a-trainmo-vingtoward the left into the section X-Y, he will transmit the codeto which the selector responds, thereby causing relay D to-becomeenergized. 'Directional relay A will then-become energized-by virtue ofa circuit which passes from terminal B,'through the back point ofcontact 18 of the despatchers relay'D then throughithe front contacts ofthe'sevcral'track relays T to THi-nclusive, front point of contact 9 ofrelay D and the directional relay A? to'terminal'O. The operation'of theremaining parts of the apparatus associated with the right-hand end ofthe stretch willbe understood from the foregoing without detailedexplanation. I

Although 'I have herein shown and describedonly one form of signalingapparatus embodying myinvention,- it is understood that variouschangesand modifications may be made thereinw-ithin the scope oftheappended claims without departing from the spirit and scope of myinvention. j

Having thus described my invention, what I claim is z 1. In combination,a stretch of 1 railway track along which tr'aflic moves in bothdirections, such stretch being divided into sec tions each of which is'providedwith the usual track'circuit i'ncludinga track relay, a

normally deenergized despatchers relay,

means'controlledfrom a remote point for energizing saiddespatchersrelay, a directional' relaycontrolled by a front contact of saiddespatchers-relay'and afront contact "of each of saidtrack relays, ahome relay,'a circuit for said home relay including a front contact ofsaid despatchers relay and a=front contact "of said directional relay'aswell as a front contact of the track relayfor the first track sectionin'said 'stretch, a slow-releasing signal relay controlled bya frontcontact of said homerelay, a signal governing traflic into saidstrechand controlled by saidsignal relay, a normally deenergizedstickrelay, a pick-up circuit for said stick relay including lee a backcontact of said first section track relay and a front contact of saidsignal relay, a stick circuit for said stick delay including a backcontact of said directional relay and a front contact of saiddespatchers relay, and

a branch for said home relay circuit around the front contact of thedirectional relay and including a front contact of said stick relay.

2. In combination, a stretch of railway track along which trafiic movesin both directions, such stretch being divided into sections each ofwhich is provided with the usual track circuit including a track relay,a switch leading from a siding into the first section of said stretch, aswitch repeater relay controlled by said switch and energized while theswitch is in normal or reverse position but deenergized during transitof the switch, a normally deenergized despatchers relay, meanscontrolled from a remote point for energizing said despatchers relay, adirectional relay controlled by a front contact of said despatchersrelay and a front contact of each of said track relays, a home relay, acircuit for said home relay including a front contact of saiddespatchers relay and a front contact of said directional relay as wellas a front contact of the track relay for the first track section insaid stretch, a slow-releasing signal relay controlled by a frontcontact of said home relay as well as by a front con tact of said switchrepeater relay, a signal governing traflic into said stretch throughsaid switch and controlled by said signal relay, a normally deenergizedstick relay, a pick-up circuit for said stick relay including a backcontact of said first section track relay and a front contact of saidsignal relay, a first stick circuit for said stick relay in- H eluding aback contact of said directional relay and a front contact of saiddespatchers relay, a second stick circuit for said stick relay includinga back contact of said directional relay and a back contact of saidswitch repeater relay, and a branch for said home relay circuit aroundthe front contact of the directional relay and including a front contactof said stick relay.

3. In combination, a stretch of railway track along which trafiic movesin both directions, such stretch being divided into sections each ofwhich is provided with the usual track circuit including a track relay,a normally deenergized despatchers relay,

" means controlled from a remote point for energizing said despatchersrelay, a directional relay, means for energizing said directional relaywhen said despatchers relay is energized provided said stretch isunoccupied, a home relay, means for energizing said home relay when saiddespatchers relay and said directional relay are energized provided thefirst section in said stretch is unoccupied, a slow-releasing signalrelay controlled by a front contact of said home relay, a signalgoverning traffic into said stretch and controlled by said signal relay,a normally deenergized stick relay, means for energizing said stickrelay when a train enters said first section provided said signal relayis energized at the time, means for subsequently keeping said stickrelay energized as long as said despatchers relay remains energized, andmeans operating when said stick relay is energized to remove said homerelay from control by said directional relay.

4c. In combination, a stretch of railway track along which trafficnormally moves in both directions, such stretch being divided intosections each of which is provided with the usual track circuitincluding a track relay, a switch leading from a siding into the firstsection of said stretch, a normally deenergized clespatchers relay,means controlled from a remote point for energizing said despatchersrelay, a directional relay, means for energizing said directional relaywhen said despatchers relay is energized provided said stretch isunoccupied, a home relay, means for energizing said home relay when saiddespatchers relay and said directional relay are energized, provided thefirst section in said stretch is unoccupied, a slow releasing signalrelay controlled by a front contact of said home relay, a signalgoverning trafiic into said stretch and controlled by said signal relay,a normally deenergized stick relay, means for energizing said stickrelay when atrain enters the said first section provided said signalrelay is energized at the time, means for subsequently keeping saidstick relay energized as long as said despatchers relay remainsenergized, other means for keeping said stick relay energized duringtransit of said switch, and means operating when said stick relay isenergized to remove said home relay from control by said directionalrelay.

In testimony whereof I afiix my signature.

PAUL P. STOKER.

